An uncommon cause of pericardial actinomycosis.

Cardiac actinomycosis is rare; the pericardium is the most frequently involved site, but myocardial, endocardial and valvular involvement have all been documented. Most cases originate from a thoracopulmonary site of actinomycosis and spread directly to the pericardium. Widespread dissemination from extrathoracic organs is uncommon; in fact actinomycosis is prevented by anatomical barriers and hematogenous diffusion is rare. We describe an uncommon case of pericardial actinomycosis due to a draining fistula from the liver to the pericardial space across the diaphragm. The massive dissemination through the fistula could explain the peculiar echocardiographic images of macroscopic, echo-reflective, irregular masses, floating in the pericardial space, probably consistent with aggregates of sulfur granules.